ARIANO DI PUGLIA, town and episcopal see, now in the province of Avellino, Campania, Italy, 1,5o9ft. above sea-level, on the railway between Benevento and Foggia, 24m. E. of the former by rail. The pop. of the commune in 1931 was 22,855. It lies in the centre of a fertile district, but has often been devastated by earthquakes ; a considerable part of the population still dwells in caves. It occupies the supposed site of Aequum Tuticum, an ancient Samnite town, a Roman post-station on the Via Traiana ; but this was probably at S. Eleuterio, 51m. north.